(a) Technical Field
The present invention relates to a dye-sensitized solar cell module and a method of manufacturing the same. More particularly, the present invention relates to a dye-sensitized solar cell module, which improves the panel performance and efficiency by increasing the effective cell area, such as the area of photo-electrodes, with respect to the panel area in a constructed panel in comparison with the prior art, and a method of manufacturing the same.
(b) Background Art
In recent years, as global warming is becoming a serious problem, technologies for utilizing environmentally friendly energies have begun emerging. Among them, the most environmentally friendly field is the solar cell field which utilizes a new and renewable energy. Solar cells utilizes silicon solar cells, thin film solar cells (which use inorganic materials such as CIGS(Cu(InGa)Se2 (copper indium gallium selenide) and CdTe (cadmium telluride)), dye-sensitized solar cells, organic solar cells, and organic-inorganic hybrid solar cell.
Among these types solar cells, silicon solar cells have already been widely used commercially in various fields such as houses and industrial plants, but their price and installation costs are prohibitively expensive for use on products such as vehicles and machinery.
On the other hand, dye-sensitized solar cells are inexpensive compared to silicon solar cells and can achieve semi-transparent designs or other various designs. Such dye-sensitized solar cells may be applied not only to houses but also to building integrated photovoltaic (BIPV) power generation systems like silicon solar cells, and may be applied to various fields including electronic industrial fields such as home appliances, portable electronic devices, and vehicles.
These dye sensitized solar cell systems typically include a system for generating electricity by using a photoelectric conversion mechanism. This photoelectric conversion mechanism is configured to absorb visible light from a Ru-based pigment adsorbed by a TiO2 electrode and then formed into a photocurrent.
FIG. 1 is a cross-sectional view illustrating a conventional dye-sensitized solar cell module. As illustrated, the dye-sensitized solar cell module 1 includes a working electrode 10 on which a photo-electrode 12 to a which a dye is adsorbed is stacked, a counter electrode 20 on which a catalytic electrode 22 is stacked, and an electrolyte 30 filled within a sealed space between the working electrode 10 and the counter electrode 20.
The exemplary dye-sensitized solar cell module 1 includes: a photo-electrode 12 (i.e., a semiconductor oxide thick film) such as a TiO2 electrode to which an Ru-based dye capable of absorbing light is adsorbed, the photo-electrode 12 being stacked on a transparent conductive substrate 11 of a working electrode 10; a catalytic electrode 22 formed using platinum (Pt) and stacked on a transparent conductive substrate 21 of a counter electrode 20, and an I−/I3−-based electrolyte 30 filled in a space between the working electrode 10 and the counter electrode 20 sealed by a sealant 31 with the working electrode 10 and the counter electrode 20 being bonded to each other.
A collector may be formed in an interior of the dye-sensitized solar cell module to acquire necessary electric power by applying the dye-sensitized solar cell module to applications, making it possible to effectively collect the photocurrent. Then, the overall efficiency of a dye-sensitized solar cell is influenced by the size of a collector and a photo-electrode in a working electrode when modules are manufactured through the same process. Accordingly, the structures, shapes, and dispositions of collectors affect the overall efficiency of the system. Thus a collector capable of collecting photocurrent is required in an application with a large surface area.
This collector may include collector cells surrounded by a protective film, and a collector bottom portion with which the collector cells are connected. That is, in a general dye-sensitized solar cell module having a collector, in the case of the working electrode, silver collector cells (not shown) surrounded by protective films between TiO2 photo-electrodes 12 are formed in a linear format on the transparent conductive substrate 11. Then, the collector cells extend to the collector bottom portion 13 stacked along a periphery of the transparent conductive substrate 11 and are integrally connected to each other.
Likewise, in the counter electrode 20 also, thin collector cells (not shown) surrounded by a protective films between the catalytic electrodes 22 are formed, and the collector cells extend to the collector bottom portion 23 stacked along a periphery of the transparent conductive substrate 21 and are integrally connected to each other.
As illustrated in FIG. 1, the collector bottom portions 13 and 23 are exposed to the outside of the module 10 in the electrodes 10 and 20, and act as electrode portions electrically connecting adjacent modules when a solar cell panel is constructed by using a plurality of solar cell modules 1.
Meanwhile, in the case of small home electronic appliances, a single dye-sensitized solar cell module is sufficient for application thereof. However, for a sunroof or a panorama roof of a vehicle, a house, etc., which requires a large area, a plurality of dye-sensitized solar cell modules should be connected in series or in parallel to each other so that they can be applied to a large area. Among them, since a window for a house has a window frame, a frame structure can be applied when a dye-sensitized solar cell module is installed within the window. However, it is impossible to apply the same frame structure as one would for a house to a structure, such as a sunroof or a panorama roof of a vehicle. Therefore, it is necessary to develop a new method for fixing a dye-sensitized solar cell module.
In the dye-sensitized solar cell module 1 as described above, a photo-electrode 12, a dye, an electrolyte 30, and a catalytic electrode 22 are disposed between transparent conductive substrates 11 and 12 of a working electrode 10 and a counter electrode 20. In manufacturing such a dye-sensitized solar cell module 1, as shown in FIG. 1, the working electrode 10 and the counter electrode 20 are first bonded to each other by a sealant 31, the electrolyte 30 is injected through an electrolyte injection port 24 formed on one side of the working electrode 10, and the electrolyte injection port 24 is sealed via a sealing glass, to complete the dye-sensitized solar cell module 1.
Once individually assembled, a plurality of such dye-sensitized solar cell modules 1 manufactured in the way described above are arranged in the form of a panel, and the electrode parts exposed outside of the modules are then connected to each other, so as to complete a solar cell panel.
FIG. 2 is a sectional view of a panel constructed using conventional dye-sensitized solar cell modules, which shows the connection between the modules. As shown, the collector bottom portions 13 and 23 are exposed outside of the dye-sensitized solar cell modules 1. When two adjacent modules are arranged in the form of a panel, the two modules 1 are assembled by making the exposed electrode portions of the working electrode 10 and the counter electrode 20 vertically engage with each other, so as to make the collector bottom portions 13 and 23 of the exposed electrode portions come into contact each other.
In order to connect the electrode portions of adjacent modules 1 with each other as described above, the electrode portions are often exposed on the outer surface of the modules. Further, the electrode portions should not be connected to each other when the outer peripheries of the working electrode 10 and the counter electrode 20 in the modules are aligned to exactly coincide with each other. Instead, the electrode portions should be connected to each other when the outer edge of the counter electrode 20 and the outer edge of the working electrode 10 are arranged at positions further outside of corresponding edges of opposite electrodes, respectively, as shown in FIG. 1.
In other words, the electrode portions are connected to each other where the right outer edge of the working electrode 10 is arranged at a position further outside of the right outer edge of the counter electrode 20 and the left outer edge of the counter electrode 20 is arranged at a position further outside of the left outer edge of the working electrode 10.
However, in the case of bonding two electrodes while preventing the two electrodes from completely overlapping on each other as described above, the exposed portions of the electrodes are fragile and impose restrictions on the design, so as to degrade the marketability.
More specifically, when constructing a solar cell panel 100 as shown in FIGS. 2 and 3 which use a plurality of solar cell modules 1, the larger the area occupied by the exposed portions of the electrodes in the entire panel area, the smaller the effective cell area, such as an area of photo-electrodes. Due to the restrictions imposed by the exposed electrode area on the effective cell area, such as the area of photo-electrodes within the entire panel area, there limitations related to increasing the panel performance and efficiency.
Further, the formation of the electrolyte injection port 24 at the counter electrode 20 in order to enable injection of electrolyte requires an additional processing step for formation of the injection port. In blocking the electrolyte injection port 24, it is necessary to use a sealing glass 25 and an adhesive agent, such as surlyn, which increases the manufacturing cost. In addition, even after the sealing glass 25 is fixed via an adhesive agent, the sealing glass 25 may be easily detached from the electrolyte injection port 24.
As a result, the conventional structure has safety problems associated with its design, such as electrolyte leakage, and the sealing glass 25 attached over the electrolyte injection port 24 on the outer surface of the counter electrode 20 may degrade the outer appearance, so as to degrade the performance and marketability of the system.